In a unique case mixing adoption and a kind of surrogacy, a Fort Worth couple agreed to give their newborn son to their siblings, a couple unable to have children themselves.

Doctors and nurses who have worked for years in labor and delivery say they have never seen anything like this, and it's no wonder. You don't often see families like this: two brothers and two sisters making two sets of parents.

"For them to have a child for us and give it to us, they're extremely big people,” said Ryan Smith. “I don't know anybody else out there that would do that, I really don't."

"Everybody deserves a chance to be a parent,” Lindsay, the biological mother, said. "It's not that I'm giving it away. We created this child for them. It's theirs."

Lindsay said she now considers herself Christopher’s aunt. “I've referred to myself as Aunt Lindsay since he was born,” she said.

Ryan Smith said he is a proud adoptive father. "You get emotional, you really do,” he said. “You're going to be with this kid for the rest of your life. He's going to be with us. I'm going to start crying now."

One day, they plan on telling Christopher that he's adopted and his biological parents are in fact his aunt and uncle.

"It's only fair he realizes how special he is to us,” said Amy Smith. “By telling him, it's going to show him he really is loved, by us and them too."

The couples plan to formalize the adoption in the next few weeks but said they had to wait until he was born to do the legal paperwork.

Tuesday evening, Christopher left the hospital with his new adoptive parents.

"I'm happy for them,” Lindsay said after the new parents left. “Christopher is going to have a great life with them."